“Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing,” Mr. Trump said during a news conference here in an apparent reference to Mrs. Clinton’s deleted emails. “I think you will probably be rewarded mightily by our press.”

Former Central Intelligence Agency director Mike Morell was quoted as saying: “In the intelligence business, we would say that Putin had recruited Trump as an unwitting agent of the Russian Federation.”